The field of the disclosure relates generally to cooling of airfoils and, more specifically, to inserts for impingement cooling of rotary machine components.
In at least some known rotary machines, energy is extracted from a gas stream in a turbine which powers a mechanical load. During operation of the rotary machine, various hot gas path components are subjected to the high-temperature gas stream, which can induce wear in the hot gas path components. For example, air is pressurized in a compressor and mixed with fuel in a combustor for generating the stream of high-temperature gases. Generally, higher temperature gases increase performance, efficiency, and power output of the rotary machine. Thus, at least some known hot gas path components are cooled to facilitate operation of the rotary machine with the increased high-temperature gas streams. However, higher temperature gases can also increase thermal stresses and/or thermal degradation of the rotary machine components.
Some known hot gas path components include an airfoil with an internal cooling system, wherein a cooling fluid, such as bleed air extracted from a compressor or steam, is forced through plenums defined within the airfoil. This forced cooling facilitates the hot gas path components functioning in the high-temperature gas stream. At least some known plenums include an inlet opening and integrated components or inserts with a plurality of impingement openings. These components or inserts allow the cooling fluid channeled into the plenum through the plenum inlet opening to be directed by the impingement openings to impingement upon the internal surfaces of the airfoil, thus increasing the cooling of the internal components of the airfoil. However, at least some known integrated components with impingement openings cannot be easily replaced, because removal and replacement of some known integrated components would require disassembly and/or replacement of the entire airfoil. Additionally, at least some known removable inserts have a limited range for insertion depth into the plenum, as they are constrained by the dimensions of the inlet opening of the plenum. As such, these inserts may not provide for effective impingement cooling of the internal surfaces of some portions of the airfoil.